diff options
Diffstat (limited to 'absl/base')
| -rw-r--r-- | absl/base/config.h | 34 | ||||
| -rw-r--r-- | absl/base/options.h | 26 |
2 files changed, 60 insertions, 0 deletions
diff --git a/absl/base/config.h b/absl/base/config.h index 87f5b4ae4d91..edbf22468ec5 100644 --- a/absl/base/config.h +++ b/absl/base/config.h @@ -90,8 +90,42 @@ // not support forward declarations of its own types, nor does it support // user-provided specialization of Abseil templates. Code that violates these // rules may be broken without warning.) +#if !defined(ABSL_OPTION_USE_INLINE_NAMESPACE) || \ + !defined(ABSL_OPTION_INLINE_NAMESPACE_NAME) +#error options.h is misconfigured. +#endif + +// Check that ABSL_OPTION_INLINE_NAMESPACE_NAME is neither "head" nor "" +#if defined(__cplusplus) && ABSL_OPTION_USE_INLINE_NAMESPACE == 1 + +#define ABSL_INTERNAL_DO_TOKEN_STR(x) #x +#define ABSL_INTERNAL_TOKEN_STR(x) ABSL_INTERNAL_DO_TOKEN_STR(x) +#define ABSL_INTERNAL_INLINE_NAMESPACE_STR \ + ABSL_INTERNAL_TOKEN_STR(ABSL_OPTION_INLINE_NAMESPACE_NAME) + +static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != '\0', + "options.h misconfigured: ABSL_OPTION_INLINE_NAMESPACE_NAME must " + "not be empty."); +static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' || + ABSL_INTERNAL_INLINE_NAMESPACE_STR[1] != 'e' || + ABSL_INTERNAL_INLINE_NAMESPACE_STR[2] != 'a' || + ABSL_INTERNAL_INLINE_NAMESPACE_STR[3] != 'd' || + ABSL_INTERNAL_INLINE_NAMESPACE_STR[4] != '\0', + "options.h misconfigured: ABSL_OPTION_INLINE_NAMESPACE_NAME must " + "be changed to a new, unique identifier name."); + +#endif + +#if ABSL_OPTION_USE_INLINE_NAMESPACE == 0 #define ABSL_NAMESPACE_BEGIN #define ABSL_NAMESPACE_END +#elif ABSL_OPTION_USE_INLINE_NAMESPACE == 1 +#define ABSL_NAMESPACE_BEGIN \ + inline namespace ABSL_OPTION_INLINE_NAMESPACE_NAME { +#define ABSL_NAMESPACE_END } +#else +#error options.h is misconfigured. +#endif // ----------------------------------------------------------------------------- // Compiler Feature Checks diff --git a/absl/base/options.h b/absl/base/options.h index 3961e63f4e2a..592b33b734d7 100644 --- a/absl/base/options.h +++ b/absl/base/options.h @@ -185,4 +185,30 @@ #define ABSL_OPTION_USE_STD_VARIANT 2 + +// ABSL_OPTION_USE_INLINE_NAMESPACE +// ABSL_OPTION_INLINE_NAMESPACE_NAME +// +// These options controls whether all entities in the absl namespace are +// contained within an inner inline namespace. This does not affect the +// user-visible API of Abseil, but it changes the mangled names of all symbols. +// +// This can be useful as a version tag if you are distributing Abseil in +// precompiled form. This will prevent a binary library build of Abseil with +// one inline namespace being used with headers configured with a different +// inline namespace name. Binary packagers are reminded that Abseil does not +// guarantee any ABI stability in Abseil, so any update of Abseil or +// configuration change in such a binary package should be combined with a +// new, unique value for the inline namespace name. +// +// A value of 0 means not to use inline namespaces. +// +// A value of 1 means to use an inline namespace with the given name inside +// namespace absl. If this is set, ABSL_OPTION_INLINE_NAMESPACE_NAME must also +// be changed to a new, unique identifier name. In particular "head" is not +// allowed. + +#define ABSL_OPTION_USE_INLINE_NAMESPACE 0 +#define ABSL_OPTION_INLINE_NAMESPACE_NAME head + #endif // ABSL_BASE_OPTIONS_H_ |